Surface emitting laser, atomic oscillator, and manufacturing method of surface emitting laser

Abstract

A surface emitting laser includes: a substrate; and a laminated body disposed over the substrate, wherein the laminated body includes a first mirror layer disposed over the substrate, an active layer disposed over the first mirror layer, and a second mirror layer disposed over the active layer, and surface roughness Ra of an uppermost layer of the first mirror layer is greater than or equal to 0.45 nm and less than or equal to 1.0 nm.

What is claimed is: 
     
       1. A surface emitting laser comprising:
 a substrate; and 
 a laminated body disposed over the substrate, 
 wherein the laminated body includes a first mirror layer disposed over the substrate, an active layer disposed over the first mirror layer, and a second mirror layer disposed over the active layer, and 
 a surface roughness Ra of an uppermost layer of the first mirror layer that abuts the active layer is greater than or equal to 0.45 nm and less than or equal to 1.0 nm. 
 
     
     
       2. The surface emitting laser according to  claim 1 ,
 wherein the first mirror layer includes a first layer formed of AlGaAs, and a second layer formed of AlGaAs of which an Al composition is lower than that of the first layer. 
 
     
     
       3. The surface emitting laser according to  claim 2 ,
 wherein a concentration of carbon doped onto the first layer is greater than or equal to 7.5×10 17  cm −3  and less than or equal to 2.0×10 18  cm −3 . 
 
     
     
       4. An atomic oscillator comprising the surface emitting laser according to  claim 1 . 
     
     
       5. An atomic oscillator comprising the surface emitting laser according to  claim 2 . 
     
     
       6. An atomic oscillator comprising the surface emitting laser according to  claim 3 . 
     
     
       7. A manufacturing method of a surface emitting laser, comprising:
 forming a first mirror layer over a substrate; 
 forming an active layer over the first mirror layer; 
 forming a second mirror layer over the active layer; and 
 forming a laminated body by patterning the first mirror layer, the active layer, and the second mirror layer, 
 wherein in the forming of the first mirror layer, a surface roughness Ra of an uppermost layer of the first mirror layer that is configured to abut the active layer is controlled to be greater than or equal to 0.45 nm and less than or equal to 1.0 nm by controlling a concentration of carbon doped onto the first mirror layer. 
 
     
     
       8. The manufacturing method of a surface emitting laser according to  claim 7 ,
 wherein the first mirror layer includes a first layer formed of AlGaAs, and a second layer formed of AlGaAs of which an Al composition is lower than that of the first layer. 
 
     
     
       9. The manufacturing method of a surface emitting laser according to  claim 8 ,
 wherein in the forming of the first mirror layer, the concentration of the carbon doped onto the first layer is greater than or equal to 7.5×10 17  cm −3  and less than or equal to 2.0×10 18  cm −3 . 
 
     
     
       10. The surface emitting laser according to  claim 1 , wherein the uppermost layer of the first mirror layer directly abuts the active layer. 
     
     
       11. The manufacturing method of the surface emitting laser according to  claim 7 , wherein the uppermost layer of the first mirror layer is configured to directly abut the active layer.